JPS5838640A - Continuous casting device for thin metal sheet - Google Patents

Abstract

PURPOSE:To provide a titled device which produces a thin sheet having a good shape of end faces by constituting convergent stationary side plates which constitute a casting cavity together with circulating bodies of refractories in the upper part and quick cooling metallic plates in the lower part and providing thickness regulating rolls in succession to said plates. CONSTITUTION:A casting space is constituted of a pair of opposed endless beltlike circulating bodies 1, 2 which circulate by maintaining a clearance for holding casting metal from a region 4a for holding the molten metal up to a region 4b for cooling the solidified metallic plate and stationary side plates 3 which are disposed along the edge parts on both sides thereof. Said plates 3 are constituted of refractories 3a of a convergent shape in the upper part, quick cooling metallic plates 3b made of steel just before or after the min. clearance part where thickness regulating rolls 5, 5 are installed in succession to said refractories and supporting bars 12. The service life of the refractories 3a is prolonged by projecting the surface of the refractories 3a to the inner side from the surface of the plates 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION Regarding the present FIAFi, a continuous casting apparatus for thin sheets, we propose an apparatus for continuously casting thin metal sheets directly from molten metal without going through processes such as ingot making or rough rolling.

Metal thin plates Yr, Il! A common manufacturing method is to produce an ingot or slab from molten metal, and then hot and cold roll it into a thin plate of a predetermined thickness. Taking the manufacturing of thin steel sheets as an example,
When obtaining a product with a thickness of 0.5 to -2111111, first cast the molten steel using a continuous casting machine to a thickness of 710 to 300.
In this method, the steel ingot is cast by ingot making, and the slab is produced by blooming. Compared to other methods, this method does not require blooming in a soaking furnace, so it is superior in labor and energy savings.

However, the slab manufactured by continuous casting in the above example,
Its surface wettability was reduced to 20σ℃.

Alternatively, since it is often cooled to near normal temperature, there is a drawback that when performing hot rolling, it is necessary to soak or heat the material to a rolling temperature. Furthermore, since the slab obtained by continuous casting has the thickness mentioned above, it requires several rounds of rough rolling in order to produce a thin steel plate of the desired thickness, which requires the installation of the rolling equipment. 4, which is also expensive.

Therefore, if it were possible to weld a thin steel plate with a thickness of several I from molten steel without going through the various processes mentioned above, it would eliminate the need for a rough rolling process and a large heating furnace to reduce the thickness to the desired thickness. This greatly simplifies the process and reduces equipment and processing costs.In addition, if a thin steel plate of several thicknesses is manufactured directly from molten steel, the structure becomes finer and component segregation is reduced. Because it is extremely small, there are no surface defects such as those caused by non-uniformity of the same structure, and a thin steel sheet with excellent properties can be obtained.

Conventionally, based on this viewpoint, thin steel 1 is produced directly from molten steel!
Various attempts have been made to manufacture it, but at present they have not yet reached an industrial level. One of the reasons for this is that the thickness and width range from several hundred to several thousand. thin steel f
In order to stably manufacture thin steel sheets, it is important to have a stable and continuous supply of molten steel that corresponds to the width of the sheet. For example, when a slit-type nozzle is used, the molten metal is likely to solidify in this nozzle part and cause #iID because the thickness is thin, and the molten metal is easily eroded and cannot be used continuously for long periods of time. The main purpose of this invention is to provide a manufacturing device that can advantageously overcome the drawbacks of the conventional direct manufacturing technology for thin steel sheets using slit-type nozzles as described above. The purpose of this is to provide a device suitable for smooth continuous casting without the risk of breakage or breakout when drawing out thin plates. A description will be given based on a preferred embodiment of steel plate to continuous casting.

FIG. 7 of the drawings schematically shows the loading method of the present invention, in which the cast metal ? 0 shows a pair of endless belt-shaped circulating bodies that are disposed opposite each other and are circulated while maintaining a gap for retention.1. Both 1lIIkK of -2 are tapered fixed 9111 plates 3'ft snow distribution, and together with the above-mentioned circulating body /,-2, the entire casting space is formed.0 Among the above-mentioned casting spaces 9, the upper part corresponding to the molten metal reservoir holds the molten metal. The area 4ta has a cross-sectional shape corresponding to the plate thickness surface that is approximately triangular in shape.
It has an I-shaped shape, and there is a pair of thickness adjustment rolls at the narrowest and smallest cross-sectional area! ,! 0 thickness adjustment roll where I is placed! ,! The interval ' is approximately equal to the thickness of the product plate.0 On the other hand, the part continuing below the molten metal holding area 4ta is a solidified metal plate cooling area 41b, in which metal particles are generated and grown along the inner surface of the circulating body. The solidified shell g is rapidly cooled and becomes a thin steel plate, which is sequentially extracted as the circulating body moves. Plate cooling area: 4 tbyc, each with a water-cooled cooling board on the back? , Tsu was set up, and the circulating body /,
70 shown in the diagram is an injection nozzle that is cooling -2
In the case of the apparatus described above, the stationary side plate 3 corresponding to the molten metal holding area 4t has an inverted triangular casting space, so the drawbacks of using a slit nozzle, which had been a problem in the past, are solved. In such a casting machine, in order to smoothly continuously cast the produced thin steel sheet without cutting or bulging, the growth of the solidified shell from the fixed side plate must be controlled by the thickness adjustment roll! ,! 'It is desirable to start the solidification at a position immediately before or after the minimum gap for installation.For example, if the solidification start position is far before the minimum gap, the thickness adjustment roll! ,! In the above sense, in order to achieve smooth continuous casting along with the production of fnI plates with excellent end face shapes, the solidification start point ttp node I want to do it! Therefore, it was found that it was necessary to investigate the structure of the fixed side plate 3 that regulates the end surface of the steel plate.

Therefore, in the apparatus of the present invention, as shown in Fig. 3, a thin steel plate was continuously cast using a 9-open full-scale fM refractory placed inside an iron support frame with a fixed side plate of 3'ft. However, if the thickness of the thin steel plate was about J, it was possible to obtain a thin steel plate with a relatively good end-to-end shape, but if the thickness of the thin steel plate exceeds j y, m, the end face shape becomes irregular and the 9 degree of deterioration tends to deteriorate with the thickness of the thin steel plate to be cast, and when the thickness of the thin steel plate is about 3Q, casting accidents such as steel leakage from the short side sometimes occur. When the shape of the end face becomes irregular, the end face of the thin steel sheet obtained after finish rolling requires cutting of about 11 to 10 or so, resulting in a significant decrease in yield.

On the other hand, if the fixed side plate J is replaced with a refractory material and made entirely of copper with a water-cooled structure, the thickness is vI4 and a-
Le! , a solidified shell is generated on the short side surface before reaching the j' portion VC, making stable continuous casting impossible, such as making it impossible to reduce the thickness to a predetermined thickness.

Therefore, the present inventors proposed a method as shown in FIG.

A fixed side plate J was used in which the upper part was a refractory part/3a1 and the lower part was a rapidly cooled steel part/Jb having a water cooling structure inside. Moreover, the boundary between the refractory part/Ja and the quenched metal part/Jb is set by the thickness adjusting roll! ,! It was installed in the area immediately before or immediately after the minimum gap where ' is located. 4 having such a fixed side plate 3', we conducted direct casting experiments of thin steel plates with various thicknesses and found that even a thin steel plate of about 30 mm thick could be pulled in a relatively short casting time. A material having a favorable end-to-end shape was obtained.

However, when casting continues for a long time, the refractory part /3a undergoes fIII loss peeling, and a solidified shell is formed at the corner part /4t caused by retreating more than the so-called lower part, which forms a restraining point. This caused the solidified shell on the short side of the thin steel plate to break, resulting in a steel leakage accident and was found to have a drawback.

Therefore, in order to overcome the above-mentioned drawbacks, the present invention further proposes the following structure. That is, the fixed side plate 3' has a structure in which the surface of the upper large object part /31 protrudes from the surface of the lower rapidly cooled metal part /jb by an amount corresponding to the thickness D. According to the example, when 3-inch S1 steel with a thickness of 1 to 100 mm was cast, in both cases It is possible to perform extremely stable continuous casting even when casting is extremely stable, and by producing an appropriate solidified shell in the quenched metal plate part/3b of the stationary side plate, it is possible to not only prevent steel leakage from the short sides of the slab, but also to achieve extremely uniform casting. A thin steel plate with excellent shape was obtained.

Refractories/Ja include magnesia, alina,
Silica, alumina, zircon, zirconia, B
N and 81. Nitride such as N4 and mixtures thereof are used, and aluina-graphite, magnesia-graphite and silica can also be advantageously applied. To make it work, add /l to D and H! + is sufficient, but if you take into account the strength of the refractory, dimensional accuracy, etc.
ns or more is appropriate.As explained above, according to the present invention, thin metal sheets can be stably produced directly from molten metal, and thin sheets with excellent end face shapes can be obtained, resulting in improved product yield. You can get a product with high price and low price.

[Brief explanation of the drawing]

Figure 7 of the drawings is a route map of the casting state of the thin plate continuous casting equipment;
Figure 1 is a route diagram of the main body of the thin plate continuous casting apparatus, Figure 3 is a perspective view of a conventional fixed side plate, and Figure 7 is a partial sectional view of the fixed side plate of the present invention. (IL) and (m) of the figure are both partial sectional views showing other embodiments of the fixed side plate of the present invention. /, Ko... Circulating body, 3%3'-identification side plate, dummy molten metal holding area, gb... Solidified metal plate cooling area, j1j
'...thickness adjustment cool, d-solidified shell, 7...thin plate,
1% T...Cooling plate, 10...Injection nozzle, /C...
It fires. /2... Support frame, /jfL... Refractory part, /3b.
...Quiet-cooled gold lt plate part, /g...corner part. Figure 1 Figure 2N Figure 5 <a) <b)

Claims (1)

[Scope of Claims] 1. A pair of circulating bodies disposed opposite each other to hold cast metal over a certain distance, and disposed along both parts of the circulating tombs! In a device in which a casting space is formed by fixing the casting 7 and the plate, the casting 9
The fixed side plate of the molten metal holding area corresponding to the upper part is formed of a tapered refractory, and the fixed side plate immediately after the minimum gap of the thickness adjustment roll installation part is formed of a rapidly cooled metal plate of the pipe. A continuous casting device for thin sheets, characterized in that the thin sheets are formed in the following manner. 2. Casting with a pair of opposingly placed circulating bodies that circulate while maintaining a gap Yr for holding the cast metal at a certain distance, and a fixed side plate that is placed along both of these circulating bodies. In a device configured with a space, the fixed side plate of the molten metal holding area corresponding to the upper part of the casting space is formed of a tapered refractory, and the minimum gap of the thickness adjustment roll installation part following that is formed of a tapered refractory. A continuous thin plate casting apparatus characterized in that a stationary side plate immediately before or immediately after is formed of a negatively cooled metal plate, and a refractory surface of the stationary side plate is made to protrude internally from a surface of the square cold metal plate.